iommu/amd: Add support for multiple IRTE formats

This patch enables support for the new 128-bit IOMMU IRTE format,
which can be used for both legacy and vapic interrupt remapping modes.
It replaces the existing operations on IRTE, which can only support
the older 32-bit IRTE format, with calls to the new struct amd_irt_ops.

It also provides helper functions for setting up, accessing, and
updating interrupt remapping table entries in different mode.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>